English▸ noun a Eurasian plant related to the bedstraws, with whorls of four to six leaves.
Genera Rubia and Sherardia, family Rubiaceae: in particular R. tinctorum, formerly cultivated for its root which yields a red dye.
▪ [mass noun] a red dye or pigment obtained from the root of the madder, or a synthetic dye resembling it.
– ORIGIN Old English mædere, of Germanic origin; obscurely related to Dutch mede, in the same sense.